Rocker mill for rolling flat articles

ABSTRACT

AN OSCILLATING ROLLING MECHANISM FOR USE IN A RECIPROCATING STRIP MILL ROLLING FLAT ARTICLES OF GREAT WIDTH AND CAPABLE OF RESISTING DIRECT ROLL PRESSURE WHILE TRANSMITTING ALL BENDING MOMENTS TO THE MILL HOUSING.

Dec. 7, 1971 T. SENDZIMIR 3,625,042

ROCKER MILL FOR ROLLING FLAT ARTICLES Filed April 4, v 1969 2 Sheets-Sheet 1 I I I aa 5g 5 I204 .3" 1 66- I I LJ A764 awe/WM 7Abusz SE/voz/A me Me/vi//e, 5trass2r) Foster and Hoffman.

Dec. 7, 1971 T. SENDZIMIR ROCKER MILL FOR ROLLING FLAT ARTICLES 2 Sheets-Sheet 2 Filed April 4, 1969 F0505: SENDZ/M/P Me /v/ //e, Sim 5521 F05 ter a 170' HO Ffrnd r2 United States Patent 3,625,042 ROCKER MILL FOR ROLLING FLAT ARTICLES Tadeusz sendzimir T. Sendzimir, Inc., Waterbury, Conn. 06712 Filed Apr. 4, 1969, Ser. No. 813,544 Int. Cl. B21b 13/14, 13/20 US. Cl. 72189 20 Claims ABSTRACT OF THE DISCLOSURE An oscillating rolling mechanism for use in a reciprocating strip mill rolling flat articles of great width and capable of resisting direct roll pressure while transmitting all bending moments to the mill housing.

THE INVENTION This invention relates to the rolling mechanism for a reciprocating strip mill and represents an improvement in the design of cyclic rolling mills for rolling flat articles of great width, such as metals and non-metals suscepticle to a reducing operation, where small diameter clusterbacked work rolls are oscillated back and forth in the direction of rolling. In operation, the rolling mechanism first engages the non-reduced workpiece and continues down the roll bite while producing a plastic deformation of the workpiece, thenreverses its movement beyond the point where the workpiece has been reduced to its final gauge.

The improvement consists in providing a low-inertia carrier structure for oscillating the work rolls, intermediate rolls, if any, and the final spaced casters. The carrier is capable of transmitting the roll separating forces generated along the face of the work roll by means 0 supports provided between each two casters, directly to the rigid beam of the mill housing, so that the said carrier structure is not subjected to any bending moments.

The improvement further consists in connecting means for oscillating said carrier structure which engage it at several places along the face of the work roll, and thus relieve it from withstanding any substantial bending moments in the lateral direction, or direction of rolling.

Additionally, means are preferably provided to disengage the work roll from operating contact with the workpiece on its return stroke, so that the rolls and all their rotating backing elements continue to rotate by inertia during the idle back stroke. Thus, the only factor that limits the speed of oscillation of the mill is the force of acceleration and deceleration of the carrier structure and its contents.

These improvements as well as others, such as the relative light weight of the carrier structure, will become apparent to those skilled in the art from the drawings and description to follow.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a sectional elevational view of a rolling mill including a first embodiment of the invention described herein.

FIG. 2 is a vertical longitudinal section through the axis of work rolls in FIG. 1.

FIG. 3 is a partial horizontal sectional view of the embodiment shown in FIGS. 1 and 2, but omitting the feed rolls and the balancing mechanism.

FIG. 4 is a view similar to FIG. 3 but showing the details of a wider mill.

FIG. 5 is a schematic side elevational view showing the cross section of the rolls in the carrier structure. Superimposed over this is a diagram showing the path of the work roll.

FIG. 6 is a topview, with parts in section, of the balancing mechanism of the embodiment shown in FIGS. 1-4.

FIG. 7 is an enlarged sectional view showing details of the mechanism illustrated in FIG. 6.

FIG. 8 is a side view of the element shown in FIG. 7.

FIGS. 9, 1-0 and 11 are schematic sectional side elevational views of three further embodiments of the invention described herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to a more detailed consideration of the embodiment shown in FIG. 1, it will be observed that a slab 10 of great width in relation to the thickness of the product, i.e., to 1 or more, is being fed into the mill continuously by means of the feed rolls 12, 12a, where the slab is reduced to the thickness of a strip 10a by repeated passes of the work roll 14. Since the work roll is generally of a small diameter, it is cluster-backed by two intermediate rolls 16, 16a, which in turn are similarly backed by three rows of backing casters 18 mounted on and freely rotatable about shafts 20.

The above described elements are mounted in the carrier 22 which consists of a plurality of individual supports 24, each of which is capable of transmitting a portion of the roll-separating force from work roll 14, through intermediate rolls 16, 16a and casters 18, directly to the rigid beam 26 of the millhousing. Between said carrier 22 and said beam 26 there is provided a roller 28 throughout the width of said beam.

Additionally, wear plates 30, 30a are provided on the beam 26 and the carrier 22. The parallelism of roller 28 is assured by means of pinions 32, affixed to each end of roller 28 and to racks and 120a attached to the beam 26 and carrier 22.

The mill is driven with the aid of the rigid eccentric shaft 34 Which engages all supports 24 of the carrier 22. The action of the shaft 34 causes the carrier to oscillate back and forth thereby assuring working contact between work roll 14 and the. workpiece 10 beginning at the unreduced portion thereof and progressing down the roll bite until the finished thickness 10a is reached. Thereupon, work roll 14 is lifted out of contact with the workpiece 10a and returned to its original position at the other end of the stroke where it is again pressed against the workpiece. This action may be best illustrated by the work roll profile shown in FIG. 5.

The shaft 34 is mounted in bearings 36 which are attached to beam 26a of the housing and coupled by coupling 38 to a motor (not shown). Intermediate the shaft 34 there is provided an enlarged rigid eccentric portion 40 on which are mounted bearings 42, one for each support 24. To balance this eccentric portion, balancing fiy wheels 44 and 46 are mounted outside of bearings 36 on shaft 34.

Such low-inertia carrier 22 assures perfect backing to work roll 14 by transmitting the roll separating forces through the spaced supports 24 to the rigid beam 26 of 3 the mill housing. Further, the rigidity of the eccentric portion 40 insures parallel oscillating movement of all of the supports 24 of the carrier 22. In this way, the carrier itself can be light and consequently the mill can be driven faster to obtain greater production.

For wider mills utilizing a greater number of supports 24, it may be preferable to provide several spaced bearings 48 located on one rigid beam 50 attached to the columns 26a of the mill housing, see FIG. 4. Finally, the bearings 48 may preferably be split for easy assembly.

Where higher mill speeds are desired, even with the ultra-light carrier 22 according to the present invention, there may result in an undesirable degree of vibration. Therefore, in addition to the balancing of the eccentric shaft 34, the carrier itself is balanced. Specifically, reference is made to the item shown in the upper left portion of FIG. 1, and the structure shown in FIGS. 6-8. Here, the carrier 22 is connected by link 52 to reverse lever 54, which pivots about pin 56. The opposite end of the lever 54 is engaged with slide 58 at 60. The oscillating movement of the slide 58 is approximately opposite to the movement of the carrier 22 thereby assuring satisfactory balancing provided their masses are equal.

The weight of slide 58 is supported by track 62 which may be lined with anti-friction material. Beside balancing the mill up to the highest speeds that mechanical and structural considerations will permit, slide 58 is shown here filling an additional purpose. That is, it provides an elastic air cushion to absorb the deceleration energy of the carrier 22 and the slide 58 near the end of each stroke, and to return it to the system to help accelerate the carrier for the next stroke.

To achieve this latter purpose, the slide 58 is provided with one or more parallel cylindrical bores 64 designed to act as double-acting air cylinders, Whose piston rods 66 are connected to transverse beam 68. The transverse beam 68 is secured to the mill housing by means of bracket 70.

The rods 66 are provided with valves and outlets 72 and 76 to supply air to the left and right hand portions respectively of the cylinder 64. Controlled quantities of the gaseous medium are supplied to each part from apparatus (not shown) to bring the pressure up to the required level and to replenish any leakage therefrom. The volumes of the air spaces beyond the stroke of the piston on each side of the cylinder, as well as the air pressures, are preferably selected so as to require more energy to compress the gas on the right-hand side of the piston head 78 than on the left. In so doing, more torque is imposed on the eccentric shaft 34 during the idle stroke and that energy is then returned to the system to diminish the demand for torque during the working stroke. Thus, the air cushions also act as a fly wheel.

It will be observed that the mill represented in FIGS. 1-5 show a work roll 14 disposed above the roll bite. Ordinarily, a symmetrical cooperating lower work roll is provided, with roll carrier support and drive, identical to those provided for the upper work roll 14. While this invention contemplates two cooperating work roll assemblies, for most cases where the slab to be reduced is not very thick, a simpler mill such as illustrated herein is preferable. In this latter case, an anvil 78, which will be described presently, is backed by the lower beam 26b of the mill to take up the roll separating force.

On top of the lower beam 26b there is provided a. wedge 80 whose position lengthwise of the workpiece is controlled by two screw down means 82, one near each side of the reduced strip a. A matching wedge 84, disposed intermediate said wedge 80 and said anvil 78 is only free to move up and down. The transverse movement of the wedge 84 is restricted by guides 86. The anvil 78 is situated on top of wedge 84 and is free to slide forward against pressure of spring 122, to follow the elongation or preferably is caused to oscillate lengthwise of the strip 10a in phase with the oscillations of the work 4 roll 14 by eccentric shafts 88 synchronously driven from the main eccentric shaft 34 and linkage 90.

In the preferred embodiments, it is desirable to adjust the phase of eccentric shafts 88 to have the acceleration part of the sinus curve coincide with the second part of the plastic reduction by work roll 14, namely, when the elongation of the workpiece is rapidly increasing. And, since the work roll 14 will have a tendency to drag forward the top layer of the workpiece during said deformation, it is preferable to offset this tendency by urging the opposite face of the workpiece forward with equal force by frictional contact with the oscillating anvil 78. As a result of this action, a sounder grain structure is obtained in the rolled product.

Turning now to a consideration of some further embodiments of this invention, it will be observed that FIG. 9 shows a modified work roll assembly. This assembly, which may be defined as a rocker structure, consists of supports 24, casters 18, shafts 20, and an upper curved surface 92 in rolling contact with plate 30, affixed to the rigid beam 26. For purposes of simplification, the driving means to rock the rocker structure has not been shown. The rolling contact of the rocker structure 22, where at least one of the two mating surfaces is curvilinear, presents the additional advantage of shaping the optimal path of the work roll 14 by selecting the suitable geometry of the two mating surfaces 92 and 30. That is, it is possible to obtain a longer roll bite than the mill size would otherwise allow.

In this embodiment since the return path of the work roll 14 is identical with its working stroke, means have been provided to disengage the work roll from the workpiece during said return stroke. The disengagement is made possible by the receding anvil 94 whose up and down movement is assured by the coaction of its two supporting wedges 96 and 98. The wedge 96 is similar to the wedge 84 in that it is free to move up and down but has screws 100 or equivalent means to adjust its position lengthwise of the roll bite. The wedge 98 is moved lengthwise of the roll bite by one or more spaced cams 102 keyed on the shaft 104 located in suitable bearings afiixed to the mill housing. The shaft 104 and the cams 102 are rotated in synchronism with the main mill drive to engage the spaced rollers 106 on wedge 98 during the working stroke of the rocker structure. To adjust the anvil 94 during the return stroke, the fluid cylinder 108 urges the wedge 98 against the reduced portion of cam 102.

Since the up and down movement of the anvil 94 is controlled by the profile of cam 102, an additional advantage is obtained in that the engagement of the work roll 14 can be made gradual and progressive by suitably shaping the cams profile. Similarly, at the end of the working stroke, an optimum disengagement cycle can thus be obtained thereby avoiding roll marks on the strip 10a corresponding to the spot where the work roll leaves contact with the strip.

The embodiment shown in FIG. 11 represents an improvement over that shown in FIG. 9, in that it is possible to take a greater advantage of the low inertia rocker structure. That is, by extending its section to accommodate three shafts 20' with their backing casters 18, an additional work roll 14a can be utilized. The two work rolls will be describing cycloidal paths, but each will follow its own cycloid Y and X, for work rolls 14 and 14a respectively. This latter effect is assured by placing the axis 116 of the cylindrical rocking surface 92 offset to the rear of the vertical plane of symmetry of the rocker structure. Thus, by adding only about one-quarter to the inertia of the rocker, it is possible to make two roll passes during each stroke and thus take a much thicker slab.

FIG. 10 shows another embodiment over those described above. By providing a cylindrical rocker surface 92 whose axis is that of the work roll 14, a straight, rather than curvilinear, roll path is obtained. "In order to take advantage of this, the rolling surface 30 of the mill housing is made inclined to the direction at which feed rolls 12 and 120 are feeding the slab into the mill. This angle therefore remains constant throughout the roll bite. This arrangement has several advantages which may be listed as follows:

(1) With a straight rather than concave roll bite, the angle of entry of the work roll, for any given length of the roll bite, is smaller than is the case with a concave roll bite.

(2) For a given profile section of the rocker, it is possible to obtain a longer roll bite, therefore making it possible to accept a thicker slab as explained above.

(3) A very smooth strip can be obtained by profiling the aft portion 118 of the anvil 94 so as to make it parallel with the roll bite. In this case the roll pressure will gradually fade out at the end of each working stroke. Such profiling simplifies considerably the design of the mill in that the mill screw down is obtained by simply shifting the anvil 94 in the direction of rolling.

I claim:

1. A cyclic mill for rolling flat articles with a small diameter workroll, comprising a mill housing having first and second parallel spaced beams between which said flat articles are caused to pass, each said beam characterized by a fiat surface to define said space, and a swinging roll carrier composed of a plurality of spaced supports normal to said workroll and at least two shafts located in openings provided in each of said supports and carrying, in spaces between supports, backing casters to support said workroll during its rolling contact with the said flat articles, while the part of said carrier which is opposed to said workroll is in rolling contact with said flat surface of the said first beam for transmitting to it by each of said spaced supports a portion of the roll separating force.

2. The cyclic mill claimed in claim 1 having an eccentric shaft parallel with said workroll, said shaft having a plurality of coaxial eccentrics for engaging each of said supports of said carrier and having where necessary concentric necks between said eccentrics, located in bearings provided in a rigid beam affixed onto said mill housing.

3. A cyclic mill as claimed in claim 2 having an eccentric shaft parallel With said wonkroll, said eccentric shaft engaging all of the said vertical supports of the carrier, so that the lower semi-circle described by said eccentric causes said workroll to travel along a lowersituated path on its working stroke where it is in rolling contact with the workpiece, while the upper semi-circle described by said eccentric on the return stroke causes said workroll to travel along a higher-situated path, where it is out of contact with the workpiece.

4. The cyclic mill as claimed in claim 3, in which the carrier has three shafts parallel with the workroll located in openings provided in each of the individual supports with backing casters rotatively mounted on said shafts in spaces between said supports, said casters backing two intermediate rolls which, in turn, back the workroll.

'5. The cyclic mill according to claim 1, having a rigid eccentric shaft within said roll carrier and engaging said spaced supports, wherein the distance between the rolling contact with said surface of the first beam and the eccentric shaft is less than the distance between the wonkroll and said eccentric shaft whereby to create a leverage causing said workroll to describe a flattened elliptic path and thus to contact the workpiece on the downward stroke only.

6. The cyclic mill as claimed in claim 1 wherein said carrier is disposed on top of the workpiece and vertical balancing means are provided to prevent said carrier from losing contact with the beam of the housing in spite of forces of gravity and inertia.

7. The cyclic mill as claimed in claim 1 in which inertia means disposed on an axis roughly parallel with the movement of the carrier and as near to it as possible, are connected with it by means such as levers to cause it to swing opposite to said carrier and thereby reduce the unbalanced horizontal forces acting upon the mill housing.

8. The cyclic mill as claimed in claim 1, wherein elastic means are disposed between the carrier and the mill housing to absorb the deceleration forces required to bring the horizontal component of the motion of the carrier to a standstill, before the end of each stroke, and to deliver said stored energy back tosaid carrier in order to accelerate it in the opposite direction, whereby to reduce forces acting upon the mill drive.

9. The cyclic mill according to claim 8, in which the elastic means provided for the end of the idle stroke are made larger than the need for compensation, i.e., where some energy furnished by the drive means must be spent to compress it, said energy being used during the subsequent working (rolling) stroke, thereby creating a flywheel effect.

10. The cyclic mill according to claim 1 in which the carrier is in direct rolling contact with the rigid beam of the housing so that the workroll describes a path of cycloidal character, said path being identical for the work and idle strokes, and means causing separation of the wonkroll from the workpiece during the idle stroke.

11. The cyclic mill according to claim 10 having a workpiece supporting anvil, which along with said workpiece is caused to recede and thus avoid being in contact with the workroll during its return stroke.

12. The cyclic mill according to claim 11 in which said up and down movement of said anvil is produced by a relative movement of one of a pair of wedges in relation to the other, said wedges, in turn, resting upon the second of said rigid beams and said movement being produced by driving means synchronous with the mill drive.

13. The cyclic mill according to claim 12, wherein said relative movement of the lifting wedge is controlled at the points when the workroll engages the workpiece and also when it disengages from it so as to make said transitions gradual and thereby to obtain a product with a better surface.

14. The cyclic mill according to claim '13- in which the up and down oscillating mechanism is made to encompass the screwdown function of the mill by providing an adjustable stop-gage to limit the trip of one of the said wedges.

15. The cyclic mill according to claim 1 having an anvil below said workroll, which anvil is free to slide in the rolling direction against pressure of elastic means during the working stroke, which elastic means are free to return it to its original position during the idle return stroke.

16. The cyclic mill as claimed in claim 15 in which said forward sliding movement is assisted by power means synchronous with the mill drive and capable of exerting upon the workpiece while in the rollbite, by frictional contact, a force in the rolling direction which is approximately equal to the forward component of the roll pres sure exerted by the wonkroll upon the opposite face of the workpiece.

17. The cyclic mill as claimed in claim 1 in which the face of said carrier is convex in cross-section and in rocking contact with the fiat surface of said first beam of the housing whereby the axis of the workroll is farther away from said beam than the maximum radius of convexity, thereby to produce an elongated workroll path.

18. The cyclic mill as claimed in claim '17 in which said rocking face is a segment of a cylinder with the axis of the workroll coinciding with the axis of said cylinder to produce a straight roll path which is made inclined to the face of the workpiece by providing an inclined liner affixed to the face of said beam and an inclined exit portion of said anvil to produce an even-gage strip.

19. The cyclic mill as claimed in claim 17 in which three parallel backing shafts are provided in the carrier to support two workrolls and the axis of the cylindrical face of the rocking carrier is assymetrical to the said three backing shafts thereby causing each one of the two workrolls to describe an arc of a dilferent cycloid and thus produce a bigger reduction of the wonkpiece.

20. The cyclic mill as claimed in claim 1 where the rolling contact of said supports .with said beam consists of contact through a rotatable cylindrical body parallel 10 with said workroll and in rolling contact with the flat face of said first beam.

References Cited UNITED STATES PATENTS LOWELL A.

7/1937 Coe 72-214 2/1969 Saxl 72-189 LARSON, Primary Examiner US. Cl. X.-R. 

